共查询到20条相似文献,搜索用时 109 毫秒
1.
D. Besnard 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):207-213
The French Commissariat à l'énergie Atomique (CEA) is
currently building the Laser MegaJoule (LMJ), a 240-beam laser facility, at
the CEA Laboratory CESTA near Bordeaux. LMJ will be a cornerstone of CEA's
“Programme Simulation”, the French Stockpile Stewardship Program. LMJ is
designed to deliver about 2 MJ of 0.35 μm light to targets for high
energy density physics experiments, among which fusion experiments. LMJ
technological choices were validated with the Ligne d'Intégration Laser
(LIL), a scale 1 prototype of one LMJ bundle, built at CEA/CESTA. Plasma
experiments started at the end of 2004 on LIL, which is already open to the
scientific community through the Plasma and Lasers Institute. The
construction of the LMJ building itself started in March of 2003. LMJ will
be gradually commissioned from early 2011, and after an experimental program
to progress toward fusion, the first fusion experiments will begin late
2012. 相似文献
2.
E. I. Moses R. E. Bonanno C. A. Haynam R. L. Kauffman B. J. MacGowan R. W. Patterson Jr R. H. Sawicki B. M. Van Wonterghem 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):215-218
The National Ignition Facility (NIF) is a 192-beam laser
facility presently under construction at LLNL. When completed, NIF will be a
1.8-MJ, 500-TW ultraviolet laser system. Its missions are to obtain fusion
ignition and to perform high energy density experiments in support of the
US nuclear weapons stockpile. Four of the NIF beams have been commissioned
to demonstrate laser performance and to commission the target area including
target and beam alignment and laser timing. During this time, NIF
demonstrated on a single-beam basis that it will meet its performance goals
and demonstrated its precision and flexibility for pulse shaping, pointing,
timing and beam conditioning. It also performed four important experiments
for Inertial Confinement Fusion and High Energy Density Science. Presently,
the project is installing production hardware to complete the project in
2009 with the goal to begin ignition experiments in 2010. An integrated plan
has been developed including the NIF operations, user equipment such as
diagnostics and cryogenic target capability, and experiments and
calculations to meet this goal. This talk will provide NIF status, the plan
to complete NIF, and the path to ignition. 相似文献
3.
K. Mima K. A. Tanaka R. Kodama T. Johzaki H. Nagatomo H. Shiraga N. Miyanaga M. Murakami H. Azechi M. Nakai T. Norimatu K. Nagai T. Taguchi H. Sakagami 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):259-264
Reviewed are the present status of the fast ignition researches. Since
1997, the fast ignition experiment and theory researches have been
extensively continued at the Institute of Laser Engineering of Osaka
University. In particular, the cone-shell target experiments and simulation
research have been progressing. In order to demonstrate heating of imploded
high density plasma to the ignition temperature, in the April of 2003, the
construction of heating laser of 10 kJ/10 ps/1.06 μm (Laser for Fusion
Experiment; LFEX), for FIREX-I (Fast Ignition Realization Experiment) has
started. The fabrication of DT foam cryogenic cone target is also under
development as a collaboration program between Osaka University and NIFS (National Institute for Fusion Science). The LFEX
will be completed in 2008.
After the completion of LFEX, the foam cryogenic cone shell target
experiment will start in 2008. As a new approach toward a compact ignition,
an impact fusion has been proposed, where the ablative acceleration to the
order of 108 cm/s is the key issue. The ablation acceleration related
to the impact fusion has been explored by experiments. 相似文献
4.
P. A. Holstein M. Casanova A. Casner C. Cherfils E. Dattolo L. Disdier D. Galmiche J. Giorla M. Houry J. P. Jadaud S. Laffite S. Liberatore P. Loiseau L. Lours L. Masse M. C. Monteil O. Morice M. Naudy F. Philippe F. Poggi F. Renaud G. Riazuelo Y. Saillard P. Seytor M. Vandenboomgaerde F. Wagon 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):239-247
This article sums up the theoretical and experimental studies about
ignition. Three experiments are salient this year on the Omega laser in
collaboration with DOE laboratories (1) 3 cones of beams allow to mimic the
LMJ configuration and to get symmetry measurements. (2) We measured
perturbations due to hydro-instability in CHGe planar samples with face-on
and side-on radiographs. (3) We improved our nuclear diagnostics,
particularly the neutron image system tested on direct drive implosions. As far as LMJ target design is concerned, we defined
a preliminary domain
corresponding to the possible operation at 2ω. At 3ω we studied the low mode
instability effects on the DT deformation (due to the laser or to the
target) and on the yield. The stability is clearly improved with graded
doped CH for our nominal capsule L1215. 相似文献
5.
6.
A first set of shock timing, laser-plasma interaction, hohlraum energetics
and hydrodynamic experiments have been performed using the first 4 beams of
the National Ignition Facility (NIF), in support of indirect drive Inertial
Confinement Fusion (ICF) and High Energy Density Physics (HEDP). In
parallel, a robust set of optical and X-ray spectrometers, interferometer,
calorimeters and imagers have been activated. The experiments have been
undertaken with laser powers and energies of up to 8 TW and 17 kJ in flattop
and shaped 1–9 ns pulses focused with various beam smoothing options. The
experiments have demonstrated excellent agreement between measured and
predicted laser-target coupling in foils and hohlraums, even when extended
to a longer pulse regime unattainable at previous laser facilities,
validated the predicted effects of beam smoothing on intense laser beam
propagation in long scale-length plasmas and begun to test 3D codes by
extending the study of laser driven hydrodynamic jets to 3D geometries. 相似文献
7.
《Comptes Rendus de l''Academie des Sciences Series IV Physics》2000,1(6):671-679
This paper reviews the leading edge of the basic and applied science that use high-intensity facilities. The more than 15 000 experiments on the Nova laser since 1985 and many thousands more on other laser, particle beam, and pulsed power facilities around the world have established the new laboratory field of high-energy-density plasma physics and have furthered development of inertial fusion. High-brightness femtosecond lasers have enabled the study of matter in conditions previously unachievable on earth. These experiments and advanced calculations have established the specifications for the National Ignition Facility (NIF) and Laser MegaJoule (LMJ) and have enhanced scientific fields such as laboratory astrophysics. Science and technology developed in inertial fusion have found near-term commercial use, have enabled steady progress toward the goal of fusion ignition and gain in the laboratory, and have opened up new fields of study for the 21 st century. 相似文献
8.
极向驱动是在间接驱动构型的激光装置中,通过重瞄各束激光的位置,实现较均匀的靶丸表面激光辐照,以研究直接驱动惯性约束聚变的关键物理问题.介绍了神光III主机装置的激光排布和焦斑特点,以及激光束重瞄方法和靶丸表面激光辐照均匀性优化原则.给出了三阶和五阶超高斯近似下的激光焦斑强度分布,Φ540 μm靶丸在能量沉积满足cos2γ和cos γ假设时靶丸表面最均匀辐照的移束参数,以及二维辐射流体程序模拟最优移束时的内爆对称性结果.二维模拟结果表明,按cosγ假设移束的热斑更对称.分析了激光的束间功率不平衡、激光束重瞄精度和靶丸定位精度对靶丸表面辐照均匀性的影响.模拟结果表明,为了不显著降低靶丸表面辐照均匀性,需要将束间功率不平衡控制在5%以内,激光束重瞄精度和靶丸定位精度控制在7 μm以内. 相似文献
9.
宋鹏 翟传磊 李双贵 勇珩 齐进 杭旭登 杨容 成娟 曾清红 胡晓燕 王帅 施意 郑无敌 古培俊 邹士阳 李欣 赵益清 张桦森 张爱清 安恒斌 李敬宏 裴文兵 朱少平 《强激光与粒子束》2015,27(3):032007-68
介绍了辐射流体力学程序LARED集成程序的物理背景、模型方程、数值方法和数值算例。该程序主要应用于激光间接驱动惯性约束聚变的二维整体模拟,兼顾激光直接驱动、辐射驱动靶丸内爆过程和流体不稳定性等物理过程的数值模拟。通过与实验数据、一维辐射流体力学程序进行比对,验证了程序的可靠性。该程序实现了多群输运建模下NIF点火靶的全过程数值模拟,并已应用于惯性约束聚变的物理研究。 相似文献
10.
S. W. Haan M. C. Herrmann J. D. Salmonson P. A. Amendt D. A. Callahan T. R. Dittrich M. J. Edwards O. S. Jones M. M. Marinak D. H. Munro S. M. Pollaine B. K. Spears L. J. Suter 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):249-258
Targets intended to produce ignition on NIF are being simulated and the simulations are used to set specifications for target
fabrication and other program elements. Recent design work has focused on designs that assume only 1.0 MJ of laser energy
instead of the previous 1.6 MJ. To perform with less laser energy, the hohlraum has been redesigned to be more efficient than
previously, and the capsules are slightly smaller. Three hohlraum designs are being examined: gas fill, SiO2 foam fill, and SiO2 lined. All have a cocktail wall, and shields mounted between the capsule and the laser entrance holes. Two capsule designs
are being considered. One has a graded doped Be(Cu) ablator, and the other graded doped CH(Ge). Both can perform acceptably
with recently demonstrated ice layer quality, and with recently demonstrated outer surface roughness. Complete tables of specifications
are being prepared for both targets, to be completed this fiscal year. All the specifications are being rolled together into
an error budget indicating adequate margin for ignition with the new designs. The dominant source of error is hohlraum asymmetry
at intermediate modes 4–8, indicating the importance of experimental techniques to measure and control this asymmetry. 相似文献
11.
GU Peijun PEI Wenbing FENG Tinggui & WU Changshu Institute of Applied Physics Computational Mathematics P. O. Box Beijing China 《中国科学G辑(英文版)》2005,48(3):345-360
1 Introduction The laser-target coupling physics is a key topic in indirect-driven inertial confinement fusion (ICF) and X-ray application research[1―3]. When intense laser light irradiates the solid target, the plasmas are produced rapidly on the surface of the target. The laser en-ergy is mainly absorbed by inverse bremsstrahlung absorption, and a coronal region with high-temperature and low-density plasma is formed. Electron thermal conduction proc-ess transfers energy into over-dense re… 相似文献
12.
在直接驱动惯性约束聚变中,实现靶丸均匀辐照对靶丸压缩特性至关重要,通常要求靶丸表面辐照不均匀度小于1%.现有很多优化高功率激光装置均匀辐照性能的光束排布方案,但受到实际入射光束参量的限制,系统均匀辐照性能难以实现最优化.由于初始辐照不均匀度对靶丸对称压缩特性至关重要,为进一步提高靶丸初始辐照的均匀性,并增加系统对打靶过程中由于靶丸直径变化引起的辐照不均匀的宽容度,从而实现靶丸的中心对称压缩,本文对靶丸表面光束的辐照不均匀度进行了数学分析,并研究了不同入射光束参量下的单光束因子项及其对靶丸均匀辐照的影响.结果表明:对于已知的光束排布结构,存在最优的入射光束参量,使辐照均匀度最高.证明了通过优化入射光束参量提高系统均匀辐照性能的可行性.此外,研究表明单光束因子项与几何因子项存在一定的匹配关系,可通过分析几何因子项的特征,求取与之匹配的单光束因子项,进而获得最优的入射光束参量.本工作为直接驱动靶丸均匀辐照系统的设计和优化提供了一种有效的方法. 相似文献
13.
D. H.H. Hoffmann A. Blazevic O. N. Rosmej P. Spiller N. A. Tahir K. Weyrich T. Dafni M. Kuster P. Ni M. Roth S. Udrea D. Varentsov J. Jacoby V. Kain R. Schmidt K. Zioutas V. Mintsev V. E. Fortov B. Yu. Sharkov 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):293-300
Interaction phenomena of intense ion- and laser radiation with matter have a
large range of application in different fields of science, extending from
basic research of plasma properties to applications in energy science,
especially in inertial fusion. The heavy ion synchrotron at GSI now
routinely delivers intense uranium beams that deposit about 1 kJ/g of
specific energy in solid matter, e.g. solid lead. Our simulations show that
the new accelerator complex FAIR (Facility for Antiproton and Ion Research)
at GSI as well as beams from the CERN large hadron collider (LHC) will
vastly extend the accessible parameter range for high energy density states.
A natural example of hot dense plasma is provided by our neighbouring star
the sun, and allows a deep insight into the physics of fusion, the
properties of matter at high energy density, and is moreover an excellent
laboratory for astroparticle physics. As such the sun's interior plasma can
even be used to probe the existence of novel particles and dark matter
candidates. We present an overview on recent results and developments of
dense plasma physics addressed with heavy ion and laser beams combined with
accelerator- and nuclear physics technology. 相似文献
14.
Review of Japanese fusion program and role of inertial fusion 总被引:1,自引:0,他引:1
O. Motojima 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):219-225
The high compression of 600 times liquid density and the recent fast heating of a compressed core to 1-keV temperature have
provided proof-of-principle of the fast ignition concept, and these results have significantly contributed to approve first
phase of the Fast Ignition Realization EXperiment (FIREX) project. The goal of FIREX-I is to demonstrate fast heating of a
fusion fuel up to the ignition temperature of 5–10 keV. Although the fuel size of FIREX-I is too small to ignite, sufficient
heating will provide the scientific viability of ignition-and-burn by increasing the laser energy thereby the fuel size. Based
on the result of FIREX-I, the decision of the start of FIREX-II to achieve ignition-and-burn can be made. The FIREX program
is under the collaboration of the Institute of Laser Engineering and the National Institute for Fusion Science. 相似文献
15.
In this paper,a six-cylinder-port hohlraum is proposed to provide high symmetry flux on capsule.It is designed to ignite a capsule with 1.2-mm radius in indirect-drive inertial confinement fusion(ICF).Flux symmetry and laser energy are calculated by using three-dimensional view factor method and laser energy balance in hohlraum.Plasma conditions are analyzed based on the two-dimensional radiation-hydrodynamic simulations.There is no Y_(lm)(l≤4) asymmetry in the six-cylinder-port hohlraum when the influences of laser entrance holes(LEHs) and laser spots cancel each other out with suitable target parameters.A radiation drive with 300 eV and good flux symmetry can be achieved by using a laser energy of 2.3 MJ and peak power of 500 TW.According to the simulations,the electron temperature and the electron density on the wall of laser cone are high and low,respectively,which are similar to those of outer cones in the hohlraums on National Ignition Facility(NTF).And the laser intensity is also as low as those of NIF outer cones.So the backscattering due to laser plasma interaction(LPI) is considered to be negligible.The six-cyliner-port hohlraum could be superior to the traditional cylindrical hohlraum and the octahedral hohlraum in both higher symmetry and lower backscattering without supplementary technology at an acceptable laser energy level.It is undoubted that the hohlraum will add to the diversity of ICF approaches. 相似文献
16.
A. Faccinetto K. Thomson M. Ziskind C. Focsa 《Applied Physics A: Materials Science & Processing》2008,92(4):969-974
The response of polycyclic aromatic hydrocarbons (PAHs) to different desorption and ionization fluences has been investigated
in a laser desorption/multiphoton ionization/time-of-flight mass spectrometry scheme. The results evidence an intricate relationship
between the desorption and ionization steps, tentatively attributed to the amount of internal energy acquired by the desorbed
molecules. Different behaviors have been found for the various PAHs considered, leading to a parametric “signature” for each
species. Moreover, some insights on the fragmentation mechanism of the desorbed PAHs have been obtained, with possible interpretation
in the frame of a “ladder-switching” model. 相似文献
17.
M. Fifirig A. Cionga 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(1):33-39
We study the “coherent phase control” between the three-photon ionization by a fundamental laser field and the one-photon
ionization by its third harmonic for a hydrogen atom in its ground state. The relative phase δ of the harmonic field with
respect to the fundamental laser radiation “modulates” the interference between the two ionization channels, which is important
near the crossing points between the ionization rates of the two individual processes. Numerical results for the total ionization
rate and for the angular distribution of the photoelectrons as a function of the phase δ are presented for frequencies located
in the vicinity of the atomic resonances corresponding to the absorption of two laser photons.
Received 31 August 2000 and Received in final form 6 February 2001 相似文献
18.
H. Shu S.-Z. Fu X.-G. Huang M.-X. Ma J. Wu J.-J. Ye J.-H. He Y. Gu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):367-370
Using the ninth laser beam (converted to 2ω) of
“Shenguang-II” laser facility and the beam smoothing technology of
lens-array [Appl. Opt. 25, 377 (1986); Phys. Plasmas. 9, 3201 (1995)],
a shock wave with 700 μm (the root-mean-square of
shock breakout time (RMS) RMS ≈ 6.32 ps) flat top was created. An Al-Al
four-step target was designed to do research on shock wave stability in an
Al target. And the shock stability experiment with the Al-Al four-step
target indicated that the shock wave steadily propagated in the Al target of
thickness of about 20–45 μm under the power density of ~ 1.0×1014 W/cm2. 相似文献
19.
R. Prazeres F. Glotin C. Insa D.A. Jaroszynski J.M. Ortega 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,3(1):87-93
The two-colour operation of a Free-Electron Laser (FEL) has been demonstrated with the “CLIO” infrared facility. A two section
undulator allows the production of picosecond laser pulses at two different wavelengths and simultaneously, in a wavelength range from to , and with a wavelength separation of two colours of up to . The time overlap, between both colours, has been measured on a picosecond time scale and on a microsecond time scale. An
initial pump-probe application experiment has been performed with the two colours: stimulated emission has been measured in
a 3-level Quantum-Well system. This is the best demonstration of the stability and reliability of the two-colour laser operation.
Received: 4 November 1997 / Revised in final form: 31 March 1998 / Accepted: 10 April 1998 相似文献
20.
A high-neutron yield platform imploded by a thin shell target is generally built to probe nuclear science problems, and it has the advantages of high neutron yield, ultrashort fusion time, micro fusion zone, isotropic and monoenergetic neutron. Some analytical models have been proposed to interpret exploding-pusher target implosion driven by a long wavelength laser, whereas they are imperfect for a 0.35 μm laser implosion experiment. When using the 0.35 μm laser, the shell is ablated and accelerated to high implosion velocity governed by Newton's law, ablation acceleration and quasi-adiabatic compression models are suitable to explain the implosion of a laser direct-drive thin shell target. The new analytical model scales bang time, ion temperature and neutron yield for large variations in laser power, target radius, shell thickness, and fuel pressure. The predicted results of the analytical model are in agreement with experimental data on the Shenguang-III prototype laser facility, 100 kJ laser facility, Omega, and NIF, it demonstrates that the analytical model benefits the understanding of experiment performance and optimizing the target design of high neutron yield implosion. 相似文献